Bright rayed crater on Mercury

Bright rayed crater on Mercury

Fig. 6.10 . A relatively young crater, about 80 kilometers in diameter, has splashed bright rays far around Mercury. The bright rays are produced by impacts that excavate and eject relatively un-weathered subsurface material. Space weathering effects, such as the continued bombardment by small meteorites or solar wind particles, will eventually darken the ejected material and erase the rays from view. Bright rayed craters are also found on the Moon, and MESSENGER images, such as this one, indicate that Mercury has more of them, perhaps due to more violent impacts caused by Mercury’s greater mass and proximity to the Sun. (Courtesy of NASA/JHUAPL/CIW.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University